Can a floor board be used in place of ply or is it an overkill here ?

[platforminc]

I noticed that my builder has decided to use floorboards for a pitch roof, Isn't this supposed to be something like OSB3 /Plywood+ render board screwed ontop of it or am i missing something here ?

I am referring to the pitch roof above the proposed door. It looks like floorboards to me.

 

[sxturbo]

I think usually osb3 would be used,

But don't suppose it really matters tbh

 

[bsr]

Hi, these are called sarking boards and are not unusual especially in hilly / mountainous areas. I don't think it's an issue but will cost more than OSB.

https://www.kingspan.com/gb/en-gb/p...b/articles-and-advice/what-are-sarking-boards